When a vehicle system or device experiences an error or failure, the vehicle may generate and/or store a diagnostic trouble code (DTC). In telematics-equipped vehicles, the DTC may be transmitted cellularly to a backend or remotely located server; at times, this transmission is part of a vehicle data upload (VDU) that may occur during low or off-peak cellular-usage hours. The DTC reports one or more single incidents that have previously occurred. A vehicle user may be instructed using a vehicle message to bring the vehicle to a service center for further analysis and repair. However, at times, the source or cause of the DTC proves intermittent. And user frustration may ensue when an issue associated with the source or cause cannot be further diagnosed at the service center due to the intermittency.
DTCs do not pertain to monitoring or providing information regarding a status of the network connections that interconnect vehicle devices; instead, DTCs are generated by the vehicle devices themselves, or the electronic control unit(s) (ECUs) which couple the vehicle devices to the network connection(s). For example, DTCs do not report the health of an electronic data bus itself in the vehicle; rather, the vehicle devices (e.g., a GPS module, a tire-pressure monitoring device, etc.) typically use the data bus to report a failure or fault to another vehicle device (e.g., a diagnostics module). In fact, the process of reporting a DTC includes a presumption that the network connection is fully operational.
Thus, there is a need to monitor and determine the performance of the data bus itself. This is particularly true when streaming data is carried by the network connection. For example, where streaming video is being communicated over the network connection, video display quality may be reduced due to missing frames of data. And the reduced quality may result in user frustration. Further, the user may bring the vehicle to the service center only to discover that the reduction in display quality was temporary and intermittent and accordingly unidentifiable at the service center. This of course may result in additional user frustration and a lack of general satisfaction. Thus, there is a need to monitor and determine the performance of the data bus itself. In addition, there is a need to record sufficient data to later determine the root cause of any abnormalities thereby increasing customer satisfaction.